Cycle of Fifths?

[EoN604]

Hi all,

I remember when I was young in my piano lessons I was taught about the "Cycle of 5ths" and I remember something very fundamental 'clicking' in my head, and I also seem to recall that it just scratched the surface of something much bigger.

10 years later I have almost completely forgotten the entire concept. Would anyone be able to remind me of what it's all about, and if it does have the fundamental importance that I seem to vaguely recall?

Thanks all!

EoN

[geoslake]

http://www.google.com/search?hl=en&q=Cy ... gle+Search

[EoN604]

Touche.

So do many of you KVR'ers consciously use/apply this theory when writing music?

[JumpingJackFlash]

Hi all,

I remember when I was young in my piano lessons I was taught about the "Cycle of 5ths" and I remember something very fundamental 'clicking' in my head, and I also seem to recall that it just scratched the surface of something much bigger.

10 years later I have almost completely forgotten the entire concept. Would anyone be able to remind me of what it's all about, and if it does have the fundamental importance that I seem to vaguely recall?

Thanks all!

EoN

The cycle (or circle) of fifths is a chain of keys a perfect 5th apart (rising or falling), which in equal temperament, you can keep going up (or down) in 5ths until you get back to the original note (at a higher or lower octave), having passed through all other keys in the process. (Enharmonics may be required).

So, for example:
C,G,D,A,E,B,F#,C#,G#,D#,A#,E#,B#
And B# enharmonically, is C, which is the original note 7 octaves higher.

Or, descending:
C,F,Bb,Eb,Ab,Db,Gb,Cb,Fb,Bbb,Ebb,Abb,Dbb.
Notice, this is the same as above, only backwards (using enharmonic equivalents).

You can start on any note, and move in any direction. Because a descending 5th inverted is an ascending 4th (and vice versa), this is also known as the Cycle of Fourths (switch ascending and descending sequences above).

Note then when ascending in 5ths, each successive key will have one sharp more than the previous key. And when descending in 5ths, each successive key will have one flat more than the previous key.

Moving flatwards is most common when modulating, since the tonic of the previous key can become the dominant of the next.
For example: V-I in C major is G followed by C.
This chord of C then becomes the dominant of F major.
Then, F becomes the dominant of Bb, etc.

This gives us:

Code: Select all

C : V - I
F :     V - I
Bb:         V - I
Eb:             V - I
Ab:                 V - I
Db:                     V - I
Gb:                         V - I
Cb:                             V - I
etc.

Moving sharpwards is also fairly common.

This technique is used in everything, from classical to jazz. You don't have to go through all 11 keys, sometimes a piece just goes through a few, either very quickly, or over the course of many bars (or even movements).

Often, real sequences are used in the melody, over the cycle of 5ths. This is quite common in classical works.

[wrench45us]

the most basic chord progtression in jazz is ii V I

which in one case is dm G C which is conveniently laid out as one section of the cycle of fifths

to add interest to any progression there's the concept of backcycling which uses the cycle of 5ths to say add an em A before the dm G -- same destination, just a little more scenery on the way

with a cycle of fifths chart in front, there's also some 'tricks' with tritone substitution
instead of dm G C the G can be replaced by the chord directly across on the circle -- in this case Db for dm Db C. in jazz where every chord is 7th of some sort this works out esp well since two of the notes of G7 and Db7 are shared
(without a keyboard in front of me I would guess the B and the F -- the 3rd and the 7th of the G becoming the 7th and the 3rd of the Db -- something like that)

[MadPsyance]

I asked a similar question in this post:

http://www.kvraudio.com/forum/viewtopic.php?t=163993

And was answered quite thoroughly.

[Toxikator]

That's a cool bit about tritones being across the circle...

[VicDiesel]

That's a cool bit about tritones being across the circle...

Twelve is such a cool number. It can be divided by 1,2,3,4,6.

If you step around the circle in single steps, you go by fifths, and there are 12 steps.

If you step 2 places at a time, you get around in 6 steps, and you hit a whole tone scale.

If you step by 3, you get around in 4 steps, and you down by minor thirds: a diminished chord.

If you step by 4, you get the 3 notes of an augmented chord.

Step by 6, and you get the 2 notes of a tritone.

The only missing number in this story is 5, which is relatively prime to 12, so you have to hop 12 times (this is elementary group theory, and I'm only mentioning it because I don't get to flaunt a math degree very often on this forum), and you get a chromatic scale downward.

I leave steps of 6+n as an exercise to the reader.

Victor.

[EoN604]

Wow. It is quite amazing! Thanks for your help all! I think some experimentation is needed.

the most basic chord progtression in jazz is ii V I

Could anyone give an example of a jazz song that uses this chord progression?

[VicDiesel]

the most basic chord progtression in jazz is ii V I

Could anyone give an example of a jazz song that uses this chord progression?

The ultimate one is "Laura". (Good movie too.)

Am7 D7 G
Gm7 C7 F
Fm7 Bb7 Eb Cm
Am7 (5b) D7 G

Am7 D7 G
Gm7 C7 F
Fm7 Fo Em A7
D7 (9b) G7 C

A remarkable song, for instance in that the tonic chord, C, really only appears at the very end.

Victor.